#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
const int triggerPin = 2;
const int echoPin = 3;
const int LED1 = 4;
const int LED2 = 5;
const int LED3 = 6;
const int buzz = 7;

long durasi;
float jarak;

void setup() {
  pinMode(triggerPin, OUTPUT);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(buzz, OUTPUT);
  pinMode(echoPin, INPUT);
  lcd.backlight();
  lcd.init();
  lcd.clear();
}

void loop() {
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  durasi = pulseIn(echoPin, HIGH);
  jarak = (durasi *0.034) /2 /100;
  
  if(jarak < 1){
    digitalWrite(LED1, HIGH);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, LOW);
    digitalWrite(buzz, HIGH);
    tone(buzz, 850);
    delay(250);
    noTone(buzz);
    delay(250);
    lcd.setCursor(0, 0);
    lcd.println("JARAK: ");
    lcd.setCursor(7, 0);
    lcd.print(jarak);
    lcd.setCursor(12, 0);
    lcd.print("CM");
    lcd.setCursor(0, 1);
    lcd.print("KET: BAHAYA!!! ");
  }else 
  if(jarak <= 2 && jarak >=1 ){
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, HIGH);
    digitalWrite(LED3, LOW);
    tone(buzz,850);
    delay(1000);
    noTone(buzz);
    delay(1000);
    lcd.setCursor(0, 0);
    lcd.println("JARAK: ");
    lcd.setCursor(7, 0);
    lcd.print(jarak);
    lcd.setCursor(12, 0);
    lcd.print("M ");
    lcd.setCursor(0, 1);
    lcd.print("KET: !WASPADA!  ");
  }else 
  if(jarak > 2){
    digitalWrite(LED1, LOW);
    digitalWrite(LED2, LOW);
    digitalWrite(LED3, HIGH);
    lcd.setCursor(0, 0);
    lcd.println("JARAK: ");
    lcd.setCursor(7, 0);
    lcd.print(jarak);
    lcd.setCursor(12, 0);
    lcd.print("M ");
    lcd.setCursor(0, 1);
    lcd.print("KET: AMAN     ");
  }
}